______________________________________ GLOSSARY ______________________________________ Apparent Power The RMS current times the RMS voltage in a load. Boost Converter A switching power supply with an input inductor that stores energy and a shunt switch in parallel with the load. Produces a higher voltage at the output. Buck Converter A switching power supply that has a switch in series with an inductive- capacitive filter. Produces an output voltage lower than the input voltage Capacitor A capacitor stores electric energy, blocks the flow of direct current, and permits the flow of alternating current to a degree depending on the capacitance and the frequency. The voltage across a capacitor cannot change instantaneously. Current changes lead voltage changes in a capacitor. The relationship between current and voltage is: I = C dV/dt. Continuous Operation of a converter such that Conduction Mode switch turns on at non-zero current. (CCM) Converter A circuit for converting DC to AC. A circuit for converting AC to DC. A circuit for converting DC to DC. Current Injection Uses the instantaneous inductor current Control (CIC) as part of the control signals. Same as Peak Current Mode Control. Discontinuous Opposite of CCM. The switch turns on at Conduction Mode zero current. (DCM) Flyback Converter A buck-boost switching power supply with a single switching transistor that eliminates the output inductor. Energy is stored in the transformer primary when the transistor is conducting. When the transistor is off (the flyback period) the energy is transferred to the transformer secondary and load. Inductor An inductor stores electric energy, blocks the flow of alternating current to a degree depending on the inductance and frequency and permits the flow of direct current. The current through an inductor cannot change instantaneously. The relationship between current and voltage is: V = L di/dt. Peak Current Mode Uses the instantaneous inductor current Control as part of the control signals. Same as Current Injection Control. Power Factor The ratio of true power to apparent power as a percentage. Power factor is equal to the cosine of the phase angle between the current and the voltage when both are sinusoidal. Reactive Power The imaginary portion of apparent power. RMS Root mean squared. SMPS Switched Mode Power Supply Transformer A component that consists of two or more inductors which are coupled together by magnetic induction. The current and voltage are transformed across the transformer without changing the frequency. ##STR1## True Power The real portion of apparent power. ______________________________________